1. Field of Invention
2. Related Art
In U.S. Pat. No. 5,680,180 to Huang, a color wheel for a spatial light modulator projection system is disclosed having one green, one red and one blue portion on the wheel. If the color is out of balance, the length of one of the color segments, or the wavelength range of the color segment, can be altered to improve color balance.
In U.S. Pat. No. 5,448,314 to Heimbuch et al., color wheels are disclosed that reduce perceived color separation. One disclosed color wheel has two segments each of red, green and blue, whereas another disclosed wheel has one red, one blue and two green segments.
In U.S. Pat. No. 6,147,720 to Guerinot et al. discloses a projection system with two light sources and a single color wheel. The color wheel can be red, green, blue, cyan, magenta and yellow, or the wheel could be blue cyan and green, or green, cyan, green and blue, depending upon the type of light source and whether the light is reflected or transmitted.
In U.S. Pat. No. 5,650,832 to Poradish et al., discloses a color wheel movable in and out of the path of the light beam, in order to increase brightness of the projected image with a trade-off in color saturation. Also disclosed is a wheel with six segments, three being located radially outward from the other three and having different color saturation values from the inner three segments.
In U.S. Pat. No. 5,233,385 to Sampsell, a color wheel is disclosed that has four segments—green, blue, red and white (clear), with the white segment allowing for adding a base level of brightness, which is not controlled. In U.S. Pat. No. 6,054,832 to Kunzman et al, one or two white segments can be used selectively depending upon the frame brightness.
U.S. Pat. No. 5,868,482 to Edlinger et al. discloses structure and features of a prior art color wheel and projection system, the subject matter of which is incorporated by reference.